Vehicle-brake.



CHARLES n. r. Anniv: ann

Parana* ermee.

Grams n. COCHRAN, or CLEVELAND, omo, AssIGNoias, BY

Masiva AssrGNMENrs, 'ro TnELwnLL-PABXER ELECTRIC COMPANY, or CLEVE-VLAND, 01H10, A CORPORATION OF OHIO.

veulens-BRAKE.

Specification of Letters Patent.

Application led July 22, 1912. Serial No. 710,888.

To all 11:71 om it may concern Be 1t known that we, AHLM and CLYDE E.COCHRAN, citizens of ythe United States, residing' at Cleveland, in

the county of Cuyahoga andsState of Ohio, have invented a certain newand useful Improvement in VehicleBralres,-of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings.

The object of this invention is to provide simple mechanism foreiectively'braliing a vehiclewhether it be running forward or backward.

Our mechanism is particularly well adapted tor double-ended motor-drivenbaggage trucks which run at the saaie speed in either direction. To thisend, we apply two brakes, one especially adapted for retarding movementin one direction and the other for movement in the other direction, andwe connect these with suitable operating mechanism so that the two areconcurrently7 applied for either direction of movement. From this thereresults an equivalent braking action whichever way the vehicle is run,though in one direction one brake is more eiliective and in the otherthe other brake.

The invention is hereinafter more fully explained vand its essentialcharacteristics set out in the claims.

The drawings clearly disclose our invention. i

Figure l is a vertical, longitudinal section through a motor truckembodying the same; Fig'. 2 is an enlarged, transverse section throughthe double brake, showing the operating mechanism; Fig. 3 is a plan ofthe brake-operating mechanism on a scale reduced from Fig. 2; Fig. 4 isa diagram illustrating,r the braking action.

As shown inFig. 1, 10 represents the frame of the truck, and 11 and 12the wheels thereof. The frame is shown as intermediately dropped to alower level 13. One of the raised end portions oi' the frame housessuitable driving mechanism, and there may be driving mechanism in theother end portion it desired. The driving mechanism shown in Fig. 1 atthe left hand end of the truck, consists of suitably driven alinedshafts 15 carrying pinions 1G meshing with internal gears 1T on thecorresponding wheels 11.

CHARLES E. F.

and 21, in Fig. 1, represent a pair of platforms at the opposite ends ofthe truck, adapted to su 'port the attendant. The platforms are s own assultabl connected by a chain 24; passing over pulleys 25, so

that, Awhen one platform is depressed, the

other is thereby raised. Figli shows the parts in the position thw 'occuy when the operatory is standing on the platlform 20, and hfet truckisadapted to move toward the In the drawings we have shown our brakemechanism connected with the platforms so that, when the operatorremoves his weight from the platform he has been occupying, the brake isautomatically applied. 'This feature of applying the brake by the risingof a platform which tends to rise when the operator steps oil' of it, iscovered in a corresponding application of ours, filed concurrentlyherewith.

The present invention includes our double brake, however applied, andalso the double brake applied from opposite ends of the vehicle withoutreference to the specific means by which it is applied and withoutreference to whether the application of the brake is made by the raisingof the platform, or otherwise.

As above stated. the truck is driven hv the rotation of the drivingshafts l5. Fig. 2 shows two of these shafts housed in a differentialcasina and rotated bv suitably driven differential mechanism. This viewshows the main differential driving member B1, which is suitablyconnected by any usual means (not shown) With the live shafts 15 andcarries the spur near 33, adapted to mesh with a driving pinion on anarmature shaft (not shown) or with other suitable driving mechanism, itbeing understood that when the member 31 is rotated` thv two live shafts15 are rotated to drive the truck.

Our double brake may beapplied in any suitable form, but we find it veryconvenient toapply it on the inner periphery of the differential driver31. Tov this end, the diiierential driver is provided with two drums 34and 35. 'Within each drum are aV pair of brake shoes. Thus, within thedrum 35 are shoes 40, and 4l, pivoted `together at 4.2 on a stud whichis mounted in the differential casing. 30, and within the' 34 aresneller-.shoes 43 and '44 pivoted or'itlie stud 49. Diametricallyopposite the pivots 42 and 49, the shoes are spaced apart, and, betweenthem, are oscillatable operating blocks 45 and 46 respectively. Theseblocks are on rock shafts 47 and 48, respectively, which are jonrnaledin the differential casing 30. It will, accordingly, be seen that whenthe shafts 47 and 48 are rocked', the blocks force apart the brake shoesand thereby apply the brakes to the drums on the diiierential driver.

To rock the blocks 45 and 46, and, thereby apply the' brakes, we providethe following mechanism: The shaft 47 has rigid with it a rock arm '50,which is connected by a link 51 with the lever 52 pivoted to a framebracket at The rock shaft 48 has a rock arm 54. Depending from the endot the lever 52 and from the end of the arm 54 are links 55 and 56 whichare connected at their lower ends with an equalizing bar 57. and 81indicate tension springs, connected with the equalizing bar by links 82and 83, and tending to raise that bar and apply the brakes. Leadingdownward from the mid point of the equalizer bar is a link 58, which isconnected with a bell crank 59, suitably mounted on the fraxnebracket60. The lower end of the bell crank 59 connects with a rock arm 63sleeved on the pivot rod 64 of the platform 20 and having a rigid rockarm 65 extending beneath the platform. The bell crank 59 is alsoconnected by the link 70 with a swinging arm 71 pivoted on the bracket72 and with a link 73 leading to a rock arm 74 sleeved on the rod 75 ofthe platform 21 at the other end of the truck. Projecting from thesleeve 7 5 is a rigid rock arm 7 6 extending beneath this platform.

With the construction described, when one platform is down and the otherelevated, the different links are held in the position shown in Fig. 1,which holds bloks 45 and 46 in their mid-position with the brake shoesout of action. As soon, however, as the operators weight is removed fromthe platform, the springs 80 and 81 are enabled to draw up the equalizedbar, the links thereby moving toward the left and the holding rock arms65 and 76 rising as the platform rises.

' In this movement, the arm 54 is rocked upwardly and the lever 52 ismoved upwardly on its pivot, which rocks upwardly ,the arm 50. The twoarms 54v and 50, engaging their respective blocks from diametricallyopposite directions, it follows that the blocks are oppositely rockedwhenthe arms are raised. This movement, as will be seen, applies onebrake by rocking its block in one direction, the other brake by rockingits block in the opposite direction, and this movement is the same,whichever latform is raised.

The purpose otp rocking the two blocks 45 and 46 in opposite directionsis illustrated by the diagram in Fig. 4.' This view shows that brakewhich is designed to be most elisetive when the diii'erential driver ismoving in the direction of the arrow in this view. It will be seen that,in such movement, the brake shoe 40, which is drawn into increasinglytight engagement by the movement of the differential driver itself, isintrinsically more effective than the brake shoe 41. Now, by applyingthe brake shoe 41 by a right hand turn of the block 46, we cause thepoint of application of the power to be close to the outer edge of thebrake shoe; that is, the point designated :e in the drawings. This givesa more effective application than if it were at the point designated y,for two reasons: First, the theoretic lever arm x about which the forceis applied is longer than if the force were applied at the opposite coi`ner of the block marked y. Moreover, there is less material between'thepoint of application and the braking surface, and hence less loss due toelasticity.

By the `movement described, the brake shoe 4G is engaged at the point ywith an effective lever y. This is not as effective as the applicationof the shoe 41. Thus the brake shoe 41, which tends to be crowded awayfrom the braking drum by the movement of that drum, and hence, has anintrinsic braking action for thatV direction of movement less than thatof the shoe 41, is applied by a more effective leverage than the brakeshoe 40 which is intrinsically more effective.

lt will be seen. therefore, that our system uses the most eiiectivepoint of application on the shoe which is adapted to have less effectivebraking contact., and the less effective action in the more effectivelshoe, so that the brakingv action is compensated. Now, the other block45 swings in the opposite direction and piioduces a converse result withthe other brake shoes. The result, is that, whatever be the direction ofrotation of the differential driving member, that brake shoe which isadapted for the less* eii'ective braking of the vehicle when moving inthat direction, is 'applied with the most effective braking force, whilethe less effective braking force is reserved for the shoe which isintrinsically most effective.

In other words, the braking action -is acconiplished for one directionof movement primarily and compensatingly by one brake and secondarilv bythe crowding shoe of the other brake (the trailing shoe of the otherbrake being comparatively inefficient) while, for the other direction ofmovement the action is primarily by both shoes of the latter brake andsecondarily by the crowdingshoe of the .first mentioned brake. Thisgives an equal braking action, though by a different selection of brakeshoes. for both directions of movement.

The braking system above described is adfinanzen* mirably-A 4adapted fordouble endedmotor baggage trucks,'ei ther end of 'which may be thefront, and which, accordingly, run' at the' same speed in eitherdirection. The braking .being equivalent on either movement, theoperatorhas the same control of the vehicle, whichever -end is acting asthe front. Experience'.y hasj'shown that such control is not obtalnedbythe usual' brake when applied t'j a double ended vehicle, for inordinary'autom'obile practice the'reverse movement of the vehicle has somuch' 'less speed than the advance movement that 'a comparativelyineffective brake will be suicient for the reverse movement. With a-vehicle having the same speed in keach direction, however, it is, veryimportant that the braking action result equally in the two directions.Otherwise the `operator is subjected to acontinual variation in thecontrol of his vehicle as he changes from one end to the other. Ourbrake overcomes the dilicutly and renders the control constant.

' aving thus described our invention, what we claim is:

1. The combination, with a motor vehicle adapted to be driven ineither'direction; of

a pair of brakes each having a shoe and a ,rocking block for applying1t, both brakes acting on the same rotary part of the ve. hicle, one ofsaid brakes being more effective for one direction of movement, theother -more effective for the other direction of movement. j

'2. The con1bination,'with a'vehicle, of a air of brakes thereon, eachbrake com rismg a pair of pivoted shoes and a cam a apt. ed to force theshoes apart into enga ement with a driving member-common to t e two 4ojbrakes, a pair of rocking blocks between the Iso ends ofthe shoes forforcing them apart, and means for rocking said blocks Vin oppositedirections in the respective brakes.

-3. The combination, with aV wheeled vehicle'adaptcd to move in eitherdirection, of a double internal brake drum, two expanding brakes withinthe respective pdrts of saiddrum, rocking cams for eX nding said brakesrespectively, and means or concurrently rocking the. cams inopposite'directions..

- 4. The combination, with a vehicle, of a pair of brakes thereon,comprising shoes' adapted to be forced apart into engage-l ment with acommon driving member, a pair of rocking blocks between the ends of theshoes for forcing them apart, means for' pairs of brake shoes, 'one pairfor each drum,

two cams for forcing thel shoes 'of-each pair' to engage lthe respectivedrums, two mechanisms for-operating such means an equalizer`connecting'suchfoperating mechanisms, and means for operating-'theequalizer.

6. The combination, with a motor driven vehicle adapted to be moved withan equal speed in 'opposite directions, oi mechanism for driving thevehicle, 'anda pair otshoe 'brakes adapted to act on the sam'e rotatablepart of said driving mechanisim'aipair of rocking'members for applyi therespective brakes, mechanism for rocking one member in one direction,the other fin'the otherA direction to cause one brake to be mosteffective for one direction of movement the other brake most effectivefor the other ldirection of movement, an equalizer, connections betweenthe same and the two rocking mechanisms, and means for operating theequalizer similarly from either end of the vehicle.

7. The combination of a vehicle, a. pair of internal brake drums thereonrigid with each other, a pair of brake shoes within each brake drum, arocking block between the free ends of each pair of brake shoes adapt edto engagethe opposite shoes at its diametrically 4opposite corners,whereby the roc ting of a block may force apart the bra .e shoes to aply, the brake, and means for .rocking the b ocksin opposite directionsto cause both shoes lof one' brake and one the com bin'dtion of a -ptirof brakes, each brake havingv a. 'rock sha for applying it, a Pair'.fivofck arms connected with their respectiveiifshaf-an equalizer bar,a` link connectingjpitwith the respective arms, means for ih biiiing theequalizer bar to. rock one shaft one direction and one in the other, sothat the brakes are applied differently, brake a plying means at the twoends of the ve lele, and mechanism connecting the same with theequalizer.

9. In a motor vehicle, .thel combination of a rotatable drivin memberhaving a pair of brake drums rigid with each other, a pair of brakeshoes for each brakedrum, a block for each pair of brake shoes, afrockshaft for each block, whereb the rockingof the shaft may force apartt ebrake shoes to apply connecting the same with the rock shaft, wherebymovement of the bars in one direction rocks the shaft in oppositedirections,

and means for moving the equalizer.

shoes, a rock shaft for each block, whereby the brake, an equalizer bar,links and arms geequglzersrings for moving the gqualzug ar in the-l rakeapplying v`ipectiox1mez1ns "rt-,each end of the vehicle for applying theyrake, anda connection between said means andthe equalizer.

' yIn testimony whereof, we herento aifxx 10 ou;` slgnatures 1n thepresence of two wltn esses.

CHARLES E. F. AHLM. CLYDE E. COCHRAN.

' Witnesses: ALBERT; H. BATES,

BRENNAN B. WEST.

